Where to Enable Chat

What page or file should I insert the script below to enable the PHP Chat Live! application popup for end-users, and where is the best place to insert this? I want this Chat button to pop up on every page. My site is http://www.connectis.ca thanks in advance

THE CODE I NEED TO INSERT IS:

<span id=”phplive_btn_1443549693″ onclick=”phplive_launch_chat_0(0)” style=”color: #0000FF; text-decoration: underline; cursor: pointer;”></span>
<script type=”text/javascript”>

(function() {
var phplive_e_1443549693 = document.createElement(“script”) ;
phplive_e_1443549693.type = “text/javascript” ;
phplive_e_1443549693.async = true ;
phplive_e_1443549693.src = “//www.connectis.ca/chat/js/phplive_v2.js.php?v=0|1443549693|0|” ;
document.getElementById(“phplive_btn_1443549693”).appendChild( phplive_e_1443549693 ) ;
})() ;

</script>